Method of producing grain-leather.



Patented November 3, 190a.

PATENT OFFICE.

MENDEL PIANKO, OF NEWX'ORK, N. Y.

METHOD OF PRODUCING GRAIN-LEATHER.

SE'EGIFIGATION forming part of Letters Patent No. 743,099, dated November 3,1903. Application filed December 29, 1902. Serial No- 13'7,015. (No specimens.)

To CLZZ whom, it may concern.-

Be it known that I, MENDEL PIANKO, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Methods of Producing Grain-Leather; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to an improved process for the production of a commercial grainleather from those splits of a hide heretofore worthless for the purpose.

It is well known to the trade that the buffing and the grain or hide split are the only splits of a. skin which are of value for the production of a commercial grain-leather, and of these the hide-split is practically the sole grain-split of the skin, as the buffing is very thin and useless for many purposes. It has proved impossible up to the present time to produce a grain-surface on any of the flesh-splits, owing to their porosity and roughness, and as a skin will yield two or more flesh-splits and but one hide-split it follows that a method that will permit the use of the flesh-splits as a grain-leather will be of great value to the trade. I have discovered a method of treatment of such fleshsplits which will result in a surface of such evenness and density as to receive and hold a grain, the treatment resulting in a leather in many respects superior to the grain-leather of the hide-split. I

In carrying out my method the flesh-split after usual initial treatment is coated on one surface with a thin layer of plastic cement, such as rubber cement, and allowed to become thoroughly dry. The coated surface is then smoothed by pressure, as by rolling or otherwise. If the leather is to be colored, as will probably be the case in most instances, I subject the split to a dye-bath or, if preferred, coat the proper surface with the dye by a brush or otherwise before applying the cement coating. The cement coating after pressure thereon firmly unites the rough projections of the flesh-split with the bodythereof, resulting in a smooth surface which will readily receive and hold a grain, it being understood that the split after being subjected to the treatment described is to be grained- In the use of the dye, which is. preferably 7 of a penetrating nature, before applying the cement coating I gain a material advantage in that the porous-nature of the flesh-split will readily and deeply absorb the dye and the finished leather will stand considerable wear or breaking without showing the natural color of the split.

The use of the cement produces a soft pliable surface, and the leather produced by my method may be boarded to soften it to any degree desired, which advantage is not present in the hide-split, as the same has to be very carefully boarded and to a comparatively slight extent, as care must be taken not to open or break the grain, which would render the leather valueless. Experience has demonstrated that the split treated by -my process may be boarded to any degree desired without in any manner interfering with the surface.

- It is to be understood that the leather produced by my method is to be finished by any of the usual methods, such as painting or the like, and in connection with the finishing I have found that some finishing compositions in use by the trade will not stick or properly adhere to the cement coating of my process, and therefore when it is desired 'to use such finishing compound I dust the coating of cement while in a comparatively wet state with material of such nature as to cause a union between the cement and the finishing composition, such material being of course colored to correspond with the leather coloring, if any. I prefer to use leather-dust, thus producing practically a leather surface to receive the finishing, though itis to be understood that such material is not necessary except with a finishing composition which will not unite with the cement coating, and

is only mentioned to adapt my leather for use with any and all finishing compounds known to the trade.

The leather produced by my process possesses many advantages over the grain-leather produced from the hide-split which render it superior to such leather. For example, my leather may be softened or rendered pliable to any degree desired, While the hide-split can only be softened slightly, and even this must be performed with great care. Again, by my process a grain-leather is produced which is tougher and stronger than any heretofore known, as the trade fully recognizes the fact that the flesh-splits are tougher and stronger than the hide-splits.

Another decided advantage resulting from my invention resides in the fact that the hidesplits being nearer the outer surface of the skin of the animal are nearly always imperfect, as is well known, while the flesh-splits are practically always perfect, so that the grain-leather produced from such flesh-splits are practically perfect, avoiding the patching and dootoring at present resorted to in order to produce a comparatively perfect hide of grain-leather. I also gain a secondary advantage from the use of the rubbercement coating used in my process, in thatit makes a practically waterproof surface, especially adapting my leather for use in certain trades, as in making shoe-uppers or the like.

I believe myself to be the first to produce a method for treating the flesh-splits of a skin to produce a commercial grain-leather and Wish it distinctly understood that the essential step in such process is coating the surface of the split with a plastic cement and rolling the same smooth after drying, the previous dyeing, herein described, being necessary only to produce the coloring desired and is of course omitted entirely if natural leather is desired.

The value of the present invention to the trade will be appreciated from the statement, considering the present market values of the hide and flesh splits, that the leather produced as a result of my process completely finished and ready for sale as a grain leather costs only one-third the price of the hide or grain split (now the only one in use as a grain leather) in the raw and unfinished state.

By the term boarding as herein used I mean the well-understood operation of break ing the grain and softening the leather incident to rolling or rubbing the same over a cork or rubber faced board. The rubber cement mentioned is preferably made of pure Para gum dissolved in naphtha, turpentine, chloroform, ether, benzol, or other desirable solvent. The term painting used above refers to the finishing of the leather incident to applying a varnish of high luster to the grained leather, as is will understood by the trade.

The product above described is not claimed herein, being made the subject of a separate application filed by me in the United States Patent Office October 2, 1903, Serial No. 175,463.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The herein-described method of producing a grain-leather from the flesh-splits of a skin, which consists in spreading a thin layer of rubber cement on the surface of the split, drying the same, subjecting the surface so treated to pressure, and finally graining the split.

2. The herein-described method consisting in dyeing the split of a skin, coating the dyed surface with a layer of rubber cement, subjecting the said surface to pressure to smooth it, and finally graining the split.

3. The herein-described method consisting in coating the surface of a flesh-split of a skin with a plastic cement, lightly covering the same with a leather-dust, smoothing the surface so covered, and graining the split.

4. The herein-described method consisting in dyeing the flesh-split of a skin, coating the same with a plastic cement,dusting the cement'surface with leather-dust, and smoothing the surface so covered.

In testimony whereof I affix my signature in presence of two witnesses.

MENDEL PIANKO.

Witnesses:

DAVID W. GOULD, FRANK D. BLACKISTONE. 

